When memory is full, it takes any Xiaomi smartphone owner by surprise: At the most inopportune moment when you need to take an urgent picture or start the navigator, the screen blocks access to functions, the MIUI or HyperOS system starts to work slowly, and notifications of space shortages appear with alarming regularity.
Why is this happening on Xiaomi? Because the MIUI shell and the new HyperOS have their own caching and log-saving features, and over time, that data accumulates by taking up gigabytes of space that is not available to the user by standard methods, and understanding the structure of the Android file system is the first step to solving the problem.
In this article, we will examine not only standard cleaning methods, but also the hidden folder.thumbnails, which often “eats” up to 20 GB of space unnoticed by the owner. You will learn how to safely remove system debris, analyze storage and prevent re-overflow. Don’t rush to delete important photos, start with a competent diagnosis.
Storage Analysis: Finding Hidden Consumers
Before blindly deleting files, it is necessary to determine exactly what is taking up space. Xiaomi's built-in tools often only show the big picture, hiding the real amount of debris in system partitions. A standard analyzer may not display the cache weight of some applications or the size of recently deleted files.
Go to Settings → About Phone → Storage. Here you will see a color diagram, but it is not always accurate. For a deeper analysis, we recommend using third-party visualization utilities such as DiskUsage or Files by Google, which show a memory card where the size of each square corresponds to the weight of the file or folder.
Pay special attention to the “Other” or “System Files” section, which is often where the remnants of deleted applications, error logs and temporary update files hide, and if this partition takes more than 10-15 GB, manual cleaning through the file manager with access to hidden folders is required.
⚠️ Warning: When manually deleting files in the Android root directory, be extremely careful.Deleting system libraries (.so files) or configs can lead to a cyclical smartphone reboot.
Modern versions of Android 13 and Android 14 based on HyperOS have stricter restrictions on access to the file system, which means that some folders can be hidden from the standard Explorer. ADB-The teams we will talk about below.
Cleaning up system debris and app cache
The safest and most efficient way to free up space is to cache apps, and cache is a temporary file that speeds up the launch of programs, but eventually inflates to incredible sizes, especially social networks and instant messengers.
To clean up, go to Settings → Apps → All apps. Sort the list by memory size. The leaders are usually Telegram, WhatsApp, TikTok and YouTube. Don't delete the entire app if you don't want to lose correspondence, you better clear its cache.
Inside the settings of each heavy app, look for Memory or Storage, and it will have a "Clear Cache" button, and it's important not to confuse it with "Clear Everything" or "Erase Data" button, because the second option will delete your logins and your correspondence history.
- 🧹 Telegram: Go to the settings of the messenger → Data and memory → Use of memory → Clear the cache. You can set up auto-delete media files there.
- 📸 Instagram/TikTok: These apps don’t have a built-in full cache clearing button in their menus, so use the Android system menu or reinstall the app.
- 🛒 Marketplaces: Ozon, Wildberries, AliExpress, they accumulate a huge number of pictures of goods, and periodic cleaning of their cache is safe and effective.
☑️ Checklist for quick cleaning
Also worth checking is Xiaomi's standard Security app, run Cleanup, wait until the scan is over, and look carefully at what is being removed, often with large APK installer files that are no longer needed after installing the software.
Work with Gallery and Cloud Services
Photos and video are the main consumers of space. If you have a model with 64 or 128 GB of memory, media content will quickly fill up all available space, the problem is compounded by the fact that many users do not know that the Recycle Bin exists in a gallery where deleted photos lie for another 30 days.
The first step is to clean the cart. Open the Gallery app, go to the albums, find the Deleted folder and click Clear. Only then will the space physically vacate on the drive, and then check for duplicates that may have formed when sync failures.
The ideal solution for Google or Mi Cloud account holders is to use the “Free Space” feature, which has a button in the Google Photos app that removes images that have already been successfully uploaded to the cloud, allowing you to store the originals in high quality online, leaving only thumbnails on the phone.
| Service | Free limit | Features of compression | Automation |
|---|---|---|---|
| Google Photo | 15GB | High quality (compression) | Autoboot over Wi-Fi |
| Mi Cloud | 5GB | Original/Compressed | Deep integration with MIUI |
| Yandex Disk | 10GB | No-limit for photo (with subscription) | Autoloading folders |
| TegraDrive | Depends on the tariff. | Original | Manual setting |
Remember to check the folders of screenshots and uploaded documents. Often DCIM → Screenshots or Download accumulate hundreds of unwanted images that you took six months ago and forgot, and deleting them will give you an instant boost in free space.
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Use the Data Saving mode in instant messengers to prevent automatic uploading of videos and heavy GIFs to the phone gallery.
The secret of the folder.thumbnails and deep cleaning
This is the most important partition for those with inexplicably full memory. Android has a hidden folder called.thumbnails, located on the DCIM/.thumbnails path, where it stores thumbnails of all the photos and videos you've viewed for quick display in the gallery.
The problem is that the cleaning mechanism of this folder in MIUI and HyperOS sometimes fails. The thumbdata file can grow to 10, 20, even 50 gigabytes. For the system, it's just "Other" and you can't delete it by standard means, it reappears immediately after cleaning.
To defeat this file, you need to do a trick. First, delete the contents of the.thumbnails folder through the file manager (turning on the hidden file display). Then create a new file in the DCIM folder (not a folder!) called.thumbnails. Since there can be no two objects in the file system with the same name in the same directory, the system will not be able to create a new folder there and write garbage there.